the atmosphere and environment Flashcards
what percentage of air is oxygen and what is its liquefying temperature?
21%, -183 degree celsius
what percentage of air is nitrogen and what it is its liguefying temperature?
78%, -196 degree celsius
what percentage of air is carbon dioxide and what is its freezing point?
0.03%, -79 degree celsius
what is oxygen used for?
supports combustion, supports all living things
what is nitrogen used for?
used in the manufacture of ammonia, used by plants to produce plant proteins which are consumed by animals, used as a refigerant
where does carbon monoxide come from?
incomplete combustion of carbon-containing fuels in motor vehicles and industries
what harmful effects does carbon monoxide cause?
combines irreversibly with haemoglobin in blood to form carboxyhaemoglobin which prevents the transport of oxygen to body cells
what makes carbon monoxide so dangerous?
it is colourless and odurless
how do you prevent inhalation of carbon monoxide?
use catalytic converters fitted to motor vehicles to oxidise CO into harmless CO2
how is sulfur dioxide formed?
combustion of fossil fuels which contain sulfur impurities in power stations and factories or in volcanic eruptions
what can sulfur dioxide do to humans?
irritates eyes, lungs and breathing passages
what can sulfur dioxide do to the environment?
it can react with oxygen and dissolves in rainwater to form acid rain which corrodes limestone buildings and destroys aquatic life
how can sulfur dioxide be prevented from being released into the atmosphere?
through desulfurisation where SO2 from waste or flue gases produced by coal or oil burning power station
what are the three equations that show how desulfurisaton is conducted?
- CaCO3 (s) + SO2 (g) -> CaSO3 (s)
+ CO2 (g) - CaO (s) + SO2 (g) -> CaSO3 (s)
- CaSO3 (s) + 2 H2o (L) + 1/2 O2 (G) -> CaSO4. 2H2O
how are oxides of nitrogen produced?
nitrogen and oxygen in the air combined at high temperatures inside vehicle combustion engines as well as power plants and factories or in lightning
what does NO2 do to humans?
when inhaled, it irritates the eyes, lungs and breathing passages
what does NO2 do to the environment?
oxides of nitrogen reacts with oxygen and dissolves in rainwater to form acid rain, which corrodes l;limestone buildings and destroys aquatic life and plants + formation of photochemical smog
how can oxides of nitrogen be reduced?
catalytic converters fitted to motor vehicles to reduce NO into harmless nitrogen
how is ozone produced?
chemical reactions between oxides of nitrogen and unburnt hydrocarbons in the presence of sunlight or formed form photochemical reaction between oxygen molecules and oxygen atoms in the lower atmosphere layer
what are the harmful effects of ozone on humans?
chest pain, shortness of breath and throat irritation
what are the harmful effects of ozone on the environment?
ozone with other pollutants form the photochemical smog
how are unburnt hydrocarbons/methane produced?
incomplete combustion of carbon-containing fuels in vehicle engines / decomposition of plant and animal matter
what are the harmful effects of unburnt hydrocarbons and methane on the environment?
can form photochemical smog/methane is a greenhouse gas and excessive amounts of it can lead to global warming
how can we prevent the formation of unburnt hydrcarbons/methane?
using a catalytic converter to remove air pollutants in vehicle exhaust gases by converting harmful gases into less harmful gases
what are catalytic converters made for?
they are meant to be fitted to convert unburnt hydrocarbons, carbon monoxide, nitrogen monoxide to less harmful carbon dioxide and water vapour
what are the catalysts in a catalytic converter?
platinum, palladium, rubidium
what kind of vehicles need catalytic converters?
they require unleaded fuel
what are the reactions in a catalytic converter?
- 2CO (g) + 2NO (g) -> N2 (g) + 2CO2 (g)
- 2CO (g) + O2 (g) -> 2cO2 (g)
- 2C8H18 (l) + 25O2 (g) -> 16CO2 + 18H2O (l)
what is the process of a catalytic converter?
nitrogen oxides react with carbon monoxide to form carbon dioxide, and nitrogen and the carbon monoxide is oxidised to carbon dioxide and nitrogen monoxide is reduced to form nitrogen and more air is introduced to oxidise excess carbon monoxide and unburnt hydrocarbons to carbon dioxide and water vapour
what are the three processes that introduce carbon dioxide into the environment?
respiration, decomposition, combustion, volcanic action
what is respiration?
plants and animals undergo respiration to produce carbon dioxide, water and energy that is required for movement, growth and reproduction
what is respiration?
plants and animals undergo respiration to produce carbon dioxide, water and energy that is required for movement, growth and reproduction
what is the chemical formula for respiration?
C6H12O6 (aq) + 6O2 (G) -> 6CO2 (g) + 6H20 (l) + energy
what is the chemical formula of combustion?
CH4 (g) + 2O2 (g) -> CO2 (g) + 2H2O (g)
what are the processes that remove carbon dioxide from the environment?
photosynthesis, formation of fossil fuels
what is the ozone layer?
contains O3 and protects life on earth by absorbing strong ultraviolet radiation that comes from the Sun
what are chlorofluorocarbons?
molecules that are made up of chlorine, fluorine and carbon which damage the ozone layer due to the chlorine element
what are the effects of ozone depletion?
ocer exposure to ultraviolet radiation, which can then increase the risk of getting ksin cancer, genetic mutation, eye diseases, cataracts
what is the greenhouse effect?
warming of the Earth’s surface with heart from the Sun trapped in the atmosphere by greenhouse gases
what is global warming?
increase of Earth’s average surface temperature due to excessive effect of greenhouse gases
what are the effects of global warming?
melting of icebergs + drastic changes in global climate
